Surgery is the treatment of choice for non-small cell lung cancer (NSCLC). But even for potentially curative resection, patients often die of relapse, and five-year survival rates are about 70 percent even for stage I patients. Hence, considering the necessity of post-operative adjuvant chemotherapy, many comparative trials have been undertaken internationally as well. It is important to undertake randomized comparative trials with the survival endpoint, comparing with surgery alone, and to assess the efficacy of adjuvant chemotherapy. Cisplatin-based regimens, which are effective for anti-tumor results as a surrogate endpoint, are used routinely in adjuvant settings. However, the reliability of these adjuvant trials is not yet verified at present. This paper reports on the adjuvant chemotherapy results for NSCLC patients who had undergone a completely curative resection, considering QOL (Quality of Life) and immunity.